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Identify the column in the unit normal table for each of the following:

A. z-scores are listed in which column?
B. the area from z-scores toward the tail is listed in which column?
C. The area between a z-score and the mean is listed in which column?

User Ben Usman
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1 Answer

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Final answer:

A Z-table is used to find areas under the standard normal distribution curve. Z-scores are listed in the leftmost column. The cumulative area to the left of Z-scores is the body of the table, and the area toward the tail can be found by subtracting the left area from 1.

Step-by-step explanation:

When using a standard normal (Z) table, which represents the area under the normal distribution curve, you'll find different pieces of information in separate columns:

  • A. z-scores are typically listed in the leftmost column of a Z-table, which allows you to identify the row that corresponds to your particular Z-score of interest.
  • B. The area from the z-score toward the tail, which is generally the area to the right of the Z-score for standard Z-tables, is not listed directly. However, since most Z-tables show the cumulative area to the left of the Z-score, you can subtract this value from 1 to find the area to the right or toward the tail.
  • C. The area between a z-score and the mean is typically the body of the Z-table, which corresponds to the area under the curve to the left of the Z-score. For standard Z-tables that list the cumulative area to the left, this is the value you would read off directly for positive Z-scores. For Z-scores that are negative, the area between the mean and that Z-score would be the complement of the absolute value of that Z-score’s area to the left (found in the table).

Understanding how to read a Z-table is critical for performing calculations involving the standard normal distribution, such as finding probabilities or percentiles based on Z-scores.

User Dilshod K
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